Color change, intrapulpal temperature variation, and surface roughness of different bleaching protocols associated...

To evaluate the laboratory color change, intrapulpal temperature variation and enamel surface roughness after tooth bleaching using violet LED light (LED), with or without high concentration bleaching gels.

Dental crowns of bovine incisors were submitted to whitening protocols: Control (without treatment), 35% hydrogen peroxide (HP) and 37% carbamide peroxide (CP) associated or not with LED (LED/HP and LED/CP) or only LED. The whitening protocol consisted of three sessions of bleaching gels application for 30 minutes every 7 days or eight sessions with LED protocol. Groups (n= 10) were assessed for color (ΔE₀ ₀) and whiteness index changes (ΔWID), temperature variation (Δ°C) and surface roughness (Ra), prior to the beginning of the whitening treatment, in the last session and 14 days later. Data were analyzed by generalized linear models, Kruskal Wallis, Dunn and Mann Whitney tests (α= 0.05).

HP and CP, with or without LED, promoted greater color change than LED. LED/CP promoted higher color change than CP. LED significantly increased intrapulpal temperature compared to non-irradiated groups. No protocol promoted a significant increase in surface roughness.

The use of violet LED light could potentiate 37% carbamide peroxide effect; however, light increased the intrapulpal temperature in laboratory conditions.